Kate Middleton's masterclass in autumn/winter 2018 fashion at Kensington Palace Christmas party

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Kate Middleton is in the throes of a style revolution.

In recent weeks the mum-of-three has showcased a modern makeover, which all started with a visit to UCL in late November when she wore a trendy black hair ribbon and gold hoops.

It isn't just her accessory department that has had a contemporary upgrade, though. On Tuesday, the Duchess of Cambridge stepped out in a festive ensemble to host a Christmas party for families of the military serving overseas at Kensington Palace.

With the look, Kate managed to tick off three major autumn/winter 2018 trends to instantly become our Christmas Day outfit inspiration.

The Duchess of Cambridge arrived at Kensington Palace in a very festive ensemble (Getty Images)

1. The Cardigan

Alexander Wang Fall 2019 show (Getty Images)

Kate wore a simple black cropped cashmere button up by Brora, which retails for £209.

Whilst cardigans in recent years have been branded as passé, 2018 has seen the humble knit make the ultimate comeback and Kate championed it perfectly.

The duchess's tight-fitting, cropped silhouette instantly elevated the item from frumpy to fashionable. With the trend set to continue well into 2019, you may want to take note.

2. Colourful Tartan Check

Versace Autumn/Winter 2018 show (AFP/Getty Images)

Although a dash of red tartan at Christmas is a regular occurrence, colourful checks entered a whole new level of stylish as the print stormed the autumn/winter 2018 runways.

Kate's striking red skirt was by Emilia Wickstead, from the brand's autumn/winter 2018 collection. The British designer was one of a long list of reputable names, including Versace, Gucci and Michael Kors, who made the vibrant plaid a hero print this year.

3. The Boot and Skirt Combo

Victoria Beckham Autumn/Winter show at New York Fashion Week (AFP/Getty Images)

Usually one to pair a midi skirt with a stiletto, Kate decided to wear the pleated skirt with a knee-high black boot, which is possibly one of the most on-point pairings we've ever seen the duchess wear.

The combination has become a hit on the catwalks, street style scene, and a staple in Victoria Beckham's personal wardrobe.herefore, so we predict the look is only going to grow.

Did the duchess just give us a whole lot of unexpected Christmas dressing inspo? We think so.

More about: | Kate Middleton | Duchess of Cambridge